(i) Smoking increases the carbon monoxide (CO) content in blood and reduces the concentration of haem-bound oxygen hence there is deficiency of oxygen in the body tissues.
(ii) Tumor cells avoid detection and destruction by our immune system. Interferon like biological modifiers activate the immune system and help in destroying the tumor cells.
(iii) By chewing tobacco the nicotine reaches the blood and stimulates the adrenal glands to release adrenaline and noradrenaline, both these hormones increases the blood pressure.
